The painting at the center of The Icon Thief is basically a MacGuffin. There, I said it. At this point, I hope there isn’t any doubt about the sincerity of my respect for and fascination with Marcel Duchamp and the ways in which his example and influence are deeply entwined with the themes of this novel, to the point where the decision to structure the plot around the mystery of Étant Donnés seems all but inevitable. But it wasn’t. If I’d been ordered to change the premise to involve the theft and recovery of a different work of art entirely, I could have done so with minimal disruption to much of the surrounding story. I would have had to construct a new conspiracy theory around a different artist and write a new ending to accommodate the shift in emphasis, but perhaps seventy percent of the novel—everything involving Powell’s investigation, the Russian mob, and much of the art world material as well—would have survived intact. Would it have required major surgery? Of course. But it wouldn’t have been anywhere near as bad as the grueling rewrites that I’ve been asked to do for other projects.

That’s the nature of the MacGuffin: an object that exists to drive the plot and characters, but which could easily be replaced by something else, if necessary. And this is true even of objects that seem inextricably connected to the stories in which they appear. You could replace the Ark of the Covenant in Raiders of the Lost Ark with the Rod of Aaron or the Urim and Thummim or any number of other equivalent artifacts without changing an iota of the plot, aside from a few lines of dialogue. I’ve argued elsewhere that a good MacGuffin can immeasurably enrich the story in which it appears, or at least give the writer ideas for scenes or images that never would have occurred to him otherwise, and this is certainly true of The Icon Thief. But it says something about the nature of suspense fiction, and perhaps its limitations, that its components are so interchangeable. I knew from the beginning that this novel, as a conspiracy thriller set in the art world, would need to be structured around a particular work of art, and Étant Donnés was by far the best I found—and, if I’m going to be totally honest here, one of the best that anyone has ever found. But that doesn’t mean that something else wouldn’t have worked more or less as well.

You could even make the argument that other works of art would have been more appropriate, given the factual background of the novel itself. In Chapter 23 of The Icon Thief, Ilya finally penetrates to the art vault in which the painting is kept, after using a number of the clever tricks so dear to the heist story. Inside, he finds a rack of paintings, of which I write: “He did not give them a second glance, although one was a Braque and the other was a Bonnard.” These paintings are mentioned only in passing, but they’re really a nod to the other directions that the plot might have taken. Braque and Bonnard were two of the artists in the collection of Paul Rosenberg, an art collector who plays a crucial role in the true story that secretly lurks in the background of the novel, and if I were a real stickler for accuracy, I would have chosen one of these artists, or Picasso or Matisse, instead. If I chose Duchamp, it was only because he was the artist I wanted to write about. In fact, Rosenberg, at least to my knowledge, never collected Duchamp, although he certainly could have, and so I felt justified in awarding him this fictional painting.

Which brings us to another important point about MacGuffins. Study for Étant Donnés doesn’t actually exist, although I was careful to find a place it could have occupied in Duchamp’s catalog and to explain how it might have remained unknown to the larger art world. And the primary reason I went with a fictional painting, along with the various revelations about its provenance and history that I wanted to make, was that I needed a painting that would work as a MacGuffin. In particular, it needed to be relatively small, so that it could be smuggled unobtrusively out of Russia and so that Ilya could carry it out of the mansion under one arm—and, later in the novel, roll it up and conceal it beneath his clothes. In retrospect, this strikes me as a bit of a cheat, which is why, in Eternal Empire, I structure an important plot point around a real work of art, the Peter the Great egg made by the House of Fabergé, and take pains to characterize its appearance and provenance as accurately as possible. Here, though, the invented painting falls under the anthropic principle of this particular novel: without it, the rest of the story couldn’t exist in its current form. And this painting still has a long way to go…

Reading over my thoughts from yesterday on the concept of the MacGuffin, I realize that an attentive reader might argue that I’ve mixed up cause and effect. I imply that some MacGuffins are more interesting than others, but isn’t that just because the movies surrounding them are better at persuading me to care? Isn’t MacGuffin in a good movie always more interesting, by definition, than a similar plot point in a bad one? Take the Sankara stones. Viewers have always been divided over the merits of Indiana Jones and the Temple of Doom, which I love—but there’s no denying that the magical rocks at the heart of the story are a little lame. They’re arguably less interesting, as artifacts, than the crystal skull that so many of us would like to forget. Yet yesterday I listed them, with a completely straight face, next to the Grail and the Ark of the Covenant in a list of great MacGuffins, even though I’m still not entirely sure what those stones are supposed to do. The Sankara stones, in short, were clearly grandfathered in on account of my affection for my favorite movie franchise. Which suggests that conventional wisdom may be right, and the nature of the MacGuffin doesn’t really matter.

This is probably true, to a point. But I’d argue that while the Sankara stones may not be especially interesting, the Kali cult—with its ties to Gunga Din—certainly is. And while the stones almost certainly appeared in Temple of Doom after the decision to set the film in India had already been made, once the stones were in place, the movie found some exciting ways to use them. A good MacGuffin, you see, is one that takes a story to interesting places, both for the writer and the audience. Can it generate conflict on its own? No. But at its best, it provides the sort of richness and imaginative texture that can only make a good story better. True, an audience will always respond more to character and conflict than to a MacGuffin presented out of context. But I can’t imagine an audience that wouldn’t welcome a clever MacGuffin as a sort of bonus, a plum in the pudding of the story, or relish the chance to explore it with a hero the viewer cares about. A good MacGuffin plays the same role as the locations and gadgets in a Bond movie: no replacement for story, but still great fun when properly used.

For the writer, in turn, a good MacGuffin—that is, one that seizes the author’s own imagination and interest—can open up the action of a story in surprising ways. My first novel, The Icon Thief, is built around the theft of a painting, and for purposes of the plot, it could have been just about any work of art produced by a famous artist before a certain point in history. After weeks of reading books of art history in search of a suitable work, however, I settled on an imaginary study for Marcel Duchamp’s Étant Donnés, one of the most fascinating works of art in any museum. I could have chosen a painting by Picasso or Matisse or Bonnard, or something that wasn’t a painting at all. But once I settled on Duchamp, I found myself entering an entire world of unexplored stories and ideas. If I’d chosen something else, ninety percent of the action of the novel would have unfolded in exactly the same way (although the ending probably would have been different). Yet I can’t help but think that Duchamp gave the story greater interest, texture, and emotional depth, once I learned to care about him in the way that my characters would.

That’s why I feel that choosing an arbitrary or meaningless MacGuffin is a mistake, or at least a miscalculation: it robs the author of a valuable source of narrative inspiration, which can be used to fuel the story itself. In the end, a good MacGuffin has the same quality as any useful aspect of fiction: it opens more doors than it closes. As in improv comedy, where performers are encouraged to say “Yes, and…” to every idea, the writer looks for elements that will lead him to surprising places, rather than locking him down. The humble MacGuffin, so neglected and disdained by those who should know better, can be the engine that drives the story for both the characters and the author. It can suggest action, location, atmosphere, background—everything, in short, except conflict itself. And while it’s possible that a writer will be so entranced by his MacGuffin that he neglects to create interesting characters, a tendency that one often sees in members of the Dan Brown school, that’s going to be a risk in any case. But once the crucial elements are in place, I can’t conceive of a story that wouldn’t be enriched by the web of associations evoked by a great MacGuffin.

For the second time this week, I find myself reviewing a movie based on a beloved work of art about which I know practically nothing. Yesterday, it was the novels of John le Carré; today, it’s The Adventures of Tintin: The Secret of the Unicorn. And while I’ve always found le Carré dauntingly formidable, if anything, Hergé has the opposite problem—there’s almost too much good stuff here, and it’s all very enticing. (The A.V. Club has a nice Gateways to Geekery on the subject that seems like a good place to start.) Steven Spielberg’s earnest adaptation, while far from perfect, is enough to make me want to take the leap into the comics at last: as a character, Tintin is paper-thin, but winning, and I probably would have been obsessed by the movie that surrounds him if I’d seen it at the age of eight. As it stands, for all its energy, wit, and visual invention, it never takes hold in the way it constantly seems on the point of doing, and the problem, I think, lies in the secret of the Unicorn itself. In short, it lies in the MacGuffin.

A MacGuffin, of course, is the object or plot element that drives a work of fiction. The term was coined by Hitchcock, but Spielberg knows it as well as anyone, having structured the Indiana Jones series around three unforgettable objects: the Ark of the Covenant, the Sankara stones, and the Holy Grail. (We’ll just pretend that the crystal skull never happened, as Spielberg himself seems increasingly inclined to do.) Tintin takes its cues from Indy in more ways than one—although this may simply be a case of inspiration returning at last to its original source—so obviously the story is structured around a similar quest: three parchments, hidden within three model ships, leading to a legendary treasure. And what is the treasure, you ask? Well, it’s…treasure. Four hundredweight of pirate gold, as we’re repeatedly reminded, sunk at the bottom of the sea. That’s a lot of gold. Yet even as the movie worked its sometimes exhausting magic, I felt a bit of a sinking feeling myself, once I realized that the object of Tintin’s quest was going to be nothing but a convenient haul of pirate booty.

Conventional wisdom holds that the MacGuffin itself doesn’t matter; the important thing, we’re told, is the desire and conflict it arouses in the characters. Every few years, then, someone has the fashionable idea to construct a MacGuffin around nothing at all: the “government secrets” of North by Northwest, the mysterious briefcases of Ronin and Pulp Fiction, the Rabbit’s Foot of Mission: Impossible III. To a point, the conventional wisdom is right: we aren’t going to care about any object, no matter how shrouded in importance, if we don’t care about the characters, too. Yet part of me insists that a storyteller should at least pretend to find the MacGuffin interesting, and worth taking seriously, especially if the characters will be wholly defined by their quest. It would be one thing if Tintin had an emotional stake in the chase, or even, like Indy, an inner life, but he’s characterized solely by his pluck in pursuit of that pirate treasure. And I’m past the point where I’m intrigued by pirate treasure for its own sake.

And that’s the real problem. An interesting MacGuffin doesn’t guarantee interesting characters, but a boring one will make the characters boring, too, if the MacGuffin is all they want. A director with great stars and superb confidence in his craft, like Hitchcock or the John Huston of The Maltese Falcon, can get away with a MacGuffin spun out of thin air, but for most works of art, it’s probably safer to go with something less arbitrary. This lesson is lost, unfortunately, on writers and directors who have been told that MacGuffins don’t matter, but still haven’t figured out why. Tintin is the third movie in less than two months built around a MacGuffin that the movie barely bothers to develop, after the nuclear codes of Mission: Impossible—Ghost Protocoland the unspoken secrets of Tinker, Tailor, Soldier, Spy. Both films get away with it because of the level of skill involved, as does Tintin, to a point. But then I think of Indy at the Well of Souls, and I’m reminded that a MacGuffin can be far more. It can be something that gets in your dreams.